bagage/main.go
2021-11-20 13:42:20 +01:00

194 lines
4.7 KiB
Go

package main
import (
"context"
"fmt"
"git.deuxfleurs.fr/Deuxfleurs/bagage/s3"
"git.deuxfleurs.fr/Deuxfleurs/bagage/sftp"
"github.com/minio/minio-go/v7"
"github.com/minio/minio-go/v7/pkg/credentials"
"golang.org/x/crypto/ssh"
"io"
"io/ioutil"
"log"
"net"
"net/http"
"os"
)
func main() {
log.Println("=== Starting Bagage ===")
config := (&Config{}).LoadWithDefault().LoadWithEnv()
log.Println(config)
// Some init
os.MkdirAll(config.S3Cache, 0755)
// Launch our submodules
done := make(chan error)
go httpServer(config, done)
go sshServer(config, done)
err := <-done
if err != nil {
log.Fatalf("A component failed: %v", err)
}
}
type s3creds struct {
accessKey string
secretKey string
}
var keychain map[string]s3creds
func sshServer(dconfig *Config, done chan error) {
keychain = make(map[string]s3creds)
config := &ssh.ServerConfig{
PasswordCallback: func(c ssh.ConnMetadata, pass []byte) (*ssh.Permissions, error) {
log.Printf("Login: %s\n", c.User())
access_key, secret_key, err := LdapGetS3(dconfig, c.User(), string(pass))
if err == nil {
keychain[c.User()] = s3creds{access_key, secret_key}
}
return nil, err
},
}
privateBytes, err := ioutil.ReadFile(dconfig.SSHKey)
if err != nil {
log.Fatal("Failed to load private key", err)
}
private, err := ssh.ParsePrivateKey(privateBytes)
if err != nil {
log.Fatal("Failed to parse private key", err)
}
config.AddHostKey(private)
// Once a ServerConfig has been configured, connections can be
// accepted.
listener, err := net.Listen("tcp", "0.0.0.0:2222")
if err != nil {
log.Fatal("failed to listen for connection", err)
}
log.Printf("Listening on %v\n", listener.Addr())
for {
nConn, err := listener.Accept()
if err != nil {
log.Printf("failed to accept incoming connection: ", err)
continue
}
go handleSSHConn(nConn, dconfig, config)
}
}
func handleSSHConn(nConn net.Conn, dconfig *Config, config *ssh.ServerConfig) {
ctx, cancel := context.WithCancel(context.Background())
defer cancel()
defer nConn.Close()
// Before use, a handshake must be performed on the incoming
// net.Conn.
serverConn, chans, reqs, err := ssh.NewServerConn(nConn, config)
if err != nil {
log.Printf("failed to handshake: ", err)
}
defer serverConn.Conn.Close()
user := serverConn.Conn.User()
log.Printf("SSH connection established for %v\n", user)
// The incoming Request channel must be serviced.
go ssh.DiscardRequests(reqs)
// Service the incoming Channel channel.
for newChannel := range chans {
// Channels have a type, depending on the application level
// protocol intended. In the case of an SFTP session, this is "subsystem"
// with a payload string of "<length=4>sftp"
log.Printf("Incoming channel: %s\n", newChannel.ChannelType())
if newChannel.ChannelType() != "session" {
newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
log.Printf("Unknown channel type: %s\n", newChannel.ChannelType())
continue
}
channel, requests, err := newChannel.Accept()
if err != nil {
log.Print("could not accept channel.", err)
}
log.Printf("Channel accepted\n")
// Sessions have out-of-band requests such as "shell",
// "pty-req" and "env". Here we handle only the
// "subsystem" request.
go func(in <-chan *ssh.Request) {
for req := range in {
log.Printf("Request: %v\n", req.Type)
ok := false
switch req.Type {
case "subsystem":
log.Printf("Subsystem: %s\n", req.Payload[4:])
if string(req.Payload[4:]) == "sftp" {
ok = true
}
}
log.Printf(" - accepted: %v\n", ok)
req.Reply(ok, nil)
}
}(requests)
creds := keychain[user]
mc, err := minio.New(dconfig.Endpoint, &minio.Options{
Creds: credentials.NewStaticV4(creds.accessKey, creds.secretKey, ""),
Secure: dconfig.UseSSL,
})
if err != nil {
return
}
fs := s3.NewS3FS(mc, dconfig.S3Cache)
server, err := sftp.NewServer(ctx, channel, &fs)
if err != nil {
log.Fatal(err)
}
if err := server.Serve(); err == io.EOF {
server.Close()
log.Print("sftp client exited session.")
} else if err != nil {
log.Print("sftp server completed with error:", err)
}
}
}
func httpServer(config *Config, done chan error) {
// Assemble components to handle WebDAV requests
http.Handle(config.DavPath+"/",
BasicAuthExtract{
OnNotFound: NotAuthorized{},
OnCreds: LdapPreAuth{
WithConfig: config,
OnWrongPassword: NotAuthorized{},
OnFailure: InternalError{},
OnCreds: S3Auth{
WithConfig: config,
OnFailure: InternalError{},
OnMinioClient: WebDav{
WithConfig: config,
},
},
},
})
if err := http.ListenAndServe(config.HttpListen, nil); err != nil {
done <- fmt.Errorf("Error with WebDAV server: %v", err)
} else {
done <- nil
}
}